In data acquisition, a voltage/frequency converter can replace an analog/digital or digital/analog converter in many cases. A voltage/frequency converter emits as its output a frequency which is proportional to the input voltage instead of a binary parallel code word. One advantage is that the analog part of a circuit can be easily isolated from the digital part. Therefore, voltage/frequency converters are used in many diverse areas of electrical and electronic engineering. For example, when controlling electric motors, the actual current or voltage values can be easily integrated into a digital control system by converting these values into a sequence of pulses which are proportional to the actual current or voltage value.
Due to the small dimensions for which are available such a voltage/frequency converter, in many application cases, conventional voltage/frequency converters cannot always be used.
Conventional voltage/frequency converters also cannot be used when an extremely rapid and highly accurate digitization of the input signal having a large frequency deviation and the lowest possible costs is required.
For integrating the detection of the actual voltage or current value into a digital control system, it is desirable to convert a continuous signal at the location of its detection into a proportional frequency and transmit it in the form of pulses with a variable pulse repetition frequency. A high interference immunity is guaranteed, since only small demands are placed on the pulse shape for further processing of the pulses.
Thus, there is a need for a method and a device which realizes a quick and highly accurate voltage/frequency conversion having a large frequency deviation using simple means.